The management of Congestive Heart Failure (CHF) patients is currently based on easy-to-acquire measurements such as heart rate (HR), weight and blood pressure (BP). However, these measurements respond late to changes of the patient health status and provide limited information to personalize and adapt medication therapy.
Cardiac output (CO)—the volume of blood pumped by the left ventricle of the heart per minute—and systemic vascular resistance (SVR)—the resistance of the circulatory system to the pumping of blood through it—are both established clinical measures that respond reasonably early to changes of the health of a patient. Stroke volume (SV)—the volume of blood pumped by a ventricle per heart beat—is another useful measure of the health of the cardiovascular system of a patient. However, it is currently only possible to make reliable measurements of CO, SVR and SV in a clinical environment (such as a hospital). In particular, echocardiography currently the clinical ‘gold standard’ for non-invasive CO measurements, requires expensive, bulky equipment and well-trained operators. Impedance cardiography (ICG) has been considered as one of the most promising techniques for use in a home environment, but current implementations do not provide accurate CO readings for patients with CHF.
It is therefore desirable to provide ways to easily and reliably determine cardiac output and the other measures indicated above for a patient in unsupervised settings, such as at home, for use in monitoring the health of the cardiovascular system of the patient and adapting the dosage or type of medication prescribed to the patient to improve the management of CHF and reduce side effects of the medication.